Subtract. $\begin{aligned} 783{,}216& \\ \underline{-771{,}245}& \\ \end{aligned}$
Explanation: ${7}$ ${8}$ ${3}$ ${2}$ ${1}$ ${6}$ ${7}$ ${7}$ ${1}$ ${2}$ ${4}$ ${5}$ ${-\vphantom{0}}$ ${1}$ ${7}$ ${9}$ ${1}$ ${1}$ ${{7}}$ ${{7}}$ ${{0}}$ ${{700000} - {700000} = {0}}$ $\begin{aligned} 783{,}216& \\ \underline{-771{,}245}& \\ 11{,}971 \end{aligned}$